Alright everyone, for our first installment of Turbo Kits 101 we will be covering the turbo charger itself. Lets start with a brief history of the turbocharger and its early uses. The inventor of the turbo was a Swiss engineer, Alfred Buchi. The patent was received in 1905, however it would be 20 years later that it was put into use. Early use’s include aviation fighters that were used in both WWI and WWII. As time passed and the technology improved car and commercial use’s would later come into play. The first production vehicles that came with a turbo charger included the Oldsmobile Jetfire and the Chevrolet Corvair. Later vehicles would include the Porsche 911 which has had a turbo model available with great success for the majority of its life.
Now lets get into some of the dynamics of a turbo charger and how it operates. We are going to start with the basic fundamentals for the enthusiast that has limited knowledge on this topic. A simple summary of the turbocharger is an air moving pump that puts to use the energy of the exhaust gas as it leaves the engine. A big misconception is that the simple flow of the exhaust is what causes the turbine wheel to spin. This does play some roll, however what primarily drives the turbine is the energy released through thermal expansion inside the turbine section (hot side) of the turbo.The turbo charger consists of the turbine section and wheel, and the compressor section (cold side) and wheel. The compressor and turbine wheels are connected via a shaft that rides in the center section. This is also where all the lubrication takes place. Proper lubrication and cooling is key to the life and longevity of any turbo being that they can spin in excess of 100,000 RPM. Lubrication and cooling usually is done through both oil and coolant. When the turbine wheel starts to spin it drives the compressor wheel which causes the compression of the ambient air, which is entering the compressor cover, through the intake. The compression of this air puts it above atmospheric pressure and is then fed into the motor. This ability to maintain the air above atmospheric pressure is one of the biggest benefits to aviation engines which operate at high altitudes, where air density is much lower. This compressed air is measured in P.S.I. (pounds per square inch). Atmospheric pressure is around 14.7 P.S.I. So the reading of an automotive turbos pressure will start above this. P.S.I. is also commonly called boost in the automotive industry. Another common term you’ll hear relative to a turbo charger is lag. Lag is in reference to the difference of time between throttle operation and the power output increase. Basically how long it takes a turbo to get moving and build some steam. This delay is caused by the need for the exhaust and turbo charger to generate the energy needed to drive the turbine wheel.This time frame is often referred to as spool in the automotive industry. The lag you will see in a turbo system is relative to turbine size, compressor load and engine displacement, just to name a few.
We will cover that in next weeks installment. Keep your eyes peeled because the next article we will discuss the relationship between lag and the turbo chargers size and characteristics. We will also discuss trims AR’s and what they mean. Also, how to choose the correct turbo for your next project. I hope we gave everyone some useful information and thanks for your time.